On 1/4/08, Nick Guenther <[EMAIL PROTECTED]> wrote: > On 1/3/08, knitti <[EMAIL PROTECTED]> wrote: > > this is becoming OT, but I can't recommend storing HDDs as "real" > > backup solution either. HDDs _do_ have bitrot, and one should at least, > > say, once a year, verify that the *whole* disk is readable, ensuring that > > sectors which are not yet completely unreadable get remapped. Vaulting > > a DVD or a HDD for five years or more leaves you in both cases with the > > real possibility of data loss. > > How would you verify the whole disk is readable? And if it's all > readable, how do you ensure the data is still the same pattern you put > on before?
the posting von hannah shows what to do. Ths big picture is this: Backup (and/or archiving) is not fire-and-forget. You have to know how long you want to store this data to choose the right technology and media. And you have to have a process to verify that your data is good after this time. If you want backups for five years, and your life/business won't come to an end should you lose some data in spite having backed up, use DVDs or HDDs, verify after backup and just store the media. For more than five years and more-or-less critical data, use tape and verify every x time. If you approach ten years and up, you have to know how you get hardware to read the tapes... At least the LTO spec states that drives of the *current* generation _have to_ read and write also tapes one generation older and read tapes which are two generations older. So if you have LTO-2 tapes around, you will be able to read them with LTO-4 drives (which should be checked, but does actually work in this case). Some companies and universities with huge archives spend large sums just to copy their archived data to the newest technology every couple of years. --knitti
